Mesa (master): mesa: adjust OPCODE_IF/ ELSE BranchTarget fields to point to ELSE/ENDIF instr.

[Brian Paul]

Module: Mesa
Branch: master
Commit: ddd9729bc37f4b1098ef940da6e723743db3ded8
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ddd9729bc37f4b1098ef940da6e723743db3ded8

Author: Brian Paul <brianp at vmware.com>
Date:   Tue Dec 22 14:21:07 2009 -0700

mesa: adjust OPCODE_IF/ELSE BranchTarget fields to point to ELSE/ENDIF instr.

This is a little more logical.  Suggested in bug report 25654.

---

 src/mesa/drivers/dri/r600/r700_assembler.c |    4 ++--
 src/mesa/shader/prog_execute.c             |   10 ++++++++--
 src/mesa/shader/slang/slang_emit.c         |   22 +++++++++++++++++-----
 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/src/mesa/drivers/dri/r600/r700_assembler.c b/src/mesa/drivers/dri/r600/r700_assembler.c
index 51692a1..e464c61 100644
--- a/src/mesa/drivers/dri/r600/r700_assembler.c
+++ b/src/mesa/drivers/dri/r600/r700_assembler.c
@@ -5717,11 +5717,11 @@ GLboolean AssembleInstr(GLuint uiFirstInst,
                 return GL_FALSE;
             break;  
 
-        case OPCODE_IF   : 
+        case OPCODE_IF:
             {                
                 GLboolean bHasElse = GL_FALSE;
 
-                if(pILInst[pILInst[i].BranchTarget - 1].Opcode == OPCODE_ELSE)
+                if(pILInst[pILInst[i].BranchTarget].Opcode == OPCODE_ELSE)
                 {
                     bHasElse = GL_TRUE;
                 }
diff --git a/src/mesa/shader/prog_execute.c b/src/mesa/shader/prog_execute.c
index 56d174c..7f03452 100644
--- a/src/mesa/shader/prog_execute.c
+++ b/src/mesa/shader/prog_execute.c
@@ -910,6 +910,10 @@ _mesa_execute_program(GLcontext * ctx,
       case OPCODE_IF:
          {
             GLboolean cond;
+            ASSERT(program->Instructions[inst->BranchTarget].Opcode
+                   == OPCODE_ELSE ||
+                   program->Instructions[inst->BranchTarget].Opcode
+                   == OPCODE_ENDIF);
             /* eval condition */
             if (inst->SrcReg[0].File != PROGRAM_UNDEFINED) {
                GLfloat a[4];
@@ -929,14 +933,16 @@ _mesa_execute_program(GLcontext * ctx,
             else {
                /* go to the instruction after ELSE or ENDIF */
                assert(inst->BranchTarget >= 0);
-               pc = inst->BranchTarget - 1;
+               pc = inst->BranchTarget;
             }
          }
          break;
       case OPCODE_ELSE:
          /* goto ENDIF */
+         ASSERT(program->Instructions[inst->BranchTarget].Opcode
+                == OPCODE_ENDIF);
          assert(inst->BranchTarget >= 0);
-         pc = inst->BranchTarget - 1;
+         pc = inst->BranchTarget;
          break;
       case OPCODE_ENDIF:
          /* nothing */
diff --git a/src/mesa/shader/slang/slang_emit.c b/src/mesa/shader/slang/slang_emit.c
index e769d0d..ce3f6ab 100644
--- a/src/mesa/shader/slang/slang_emit.c
+++ b/src/mesa/shader/slang/slang_emit.c
@@ -1728,6 +1728,7 @@ emit_if(slang_emit_info *emitInfo, slang_ir_node *n)
          if (!inst) {
             return NULL;
          }
+         prog->Instructions[ifInstLoc].BranchTarget = prog->NumInstructions - 1;
       }
       else {
          /* jump to endif instruction */
@@ -1737,8 +1738,8 @@ emit_if(slang_emit_info *emitInfo, slang_ir_node *n)
          }
          inst_comment(inst, "else");
          inst->DstReg.CondMask = COND_TR;  /* always branch */
+         prog->Instructions[ifInstLoc].BranchTarget = prog->NumInstructions;
       }
-      prog->Instructions[ifInstLoc].BranchTarget = prog->NumInstructions;
       emit(emitInfo, n->Children[2]);
    }
    else {
@@ -1753,8 +1754,14 @@ emit_if(slang_emit_info *emitInfo, slang_ir_node *n)
       }
    }
 
-   if (n->Children[2]) {
-      prog->Instructions[elseInstLoc].BranchTarget = prog->NumInstructions;
+   if (elseInstLoc) {
+      /* point ELSE instruction BranchTarget at ENDIF */
+      if (emitInfo->EmitHighLevelInstructions) {
+         prog->Instructions[elseInstLoc].BranchTarget = prog->NumInstructions - 1;
+      }
+      else {
+         prog->Instructions[elseInstLoc].BranchTarget = prog->NumInstructions;
+      }
    }
    return NULL;
 }
@@ -1824,7 +1831,12 @@ emit_loop(slang_emit_info *emitInfo, slang_ir_node *n)
          assert(inst->Opcode == OPCODE_BRK ||
                 inst->Opcode == OPCODE_BRA);
          /* go to instruction at end of loop */
-         inst->BranchTarget = endInstLoc;
+         if (emitInfo->EmitHighLevelInstructions) {
+            inst->BranchTarget = endInstLoc;
+         }
+         else {
+            inst->BranchTarget = endInstLoc + 1;
+         }
       }
       else {
          assert(ir->Opcode == IR_CONT ||
@@ -1942,7 +1954,7 @@ emit_cont_break_if_true(slang_emit_info *emitInfo, slang_ir_node *n)
          }
 
          emitInfo->prog->Instructions[ifInstLoc].BranchTarget
-            = emitInfo->prog->NumInstructions;
+            = emitInfo->prog->NumInstructions - 1;
          return inst;
       }
    }